Well, it's an electric instrument (like a solid-body electric guitar or electric bass guitar), so it doesn't need the big soundbox to create reverberation and volume.

For players accustomed to the acoustic upright bull fiddle, it's an electric bass that can be played in the exact same position and with the same technique, posture, etc., as their primary instrument. And it's better for travel, of course: less bulky, less fragile, etc.

The only disadvantage I can imagine is what you already pointed out yourself ~ you don't get that real acoustic sound. If you're going electric, though, it's certainly a viable alternative. I don't see how an upright electric bass would be in any way inferior to the more common guitar-style electric bass.